This invention deals with solutions for avoiding damaging the combination, as the piston rod and/or the chamber may use a path during the stroke which is not the line or curve of the movement of the force provider, or force receiver, respectively, the last mentioned provider/receiver engaging the piston rod/chamber.
In specifically Dutch prior art of the beginning of the last century, a number of flexible transitions between the basis e.g. a foot plate and the bottom of the cylinder can be observed for classic bicycle floor pumps: a piece of rubber, enabling the cylinder to move in a cone shaped path relative to its basis, e.g. a foot plate, having the suspension of the cylinder in/on the foot plate as top of the upside down positioned cone. This enables the torso of the human user (or any other force provider and/or receiver) to move along a curve while pumping by moving the piston rod and/or the chamber, while the piston rod can slide on its own path relative to the chamber and vice versa. This eases the pumping operation for the user.
Floor pumps having a foot plate, e.g. held down to the ground by the foot of the user, and the bottom of the cylinder rigidly fastened to the foot plate, so that the above mentioned movement besides a straight line, is not possible. Many classic pumps have shown the problem that the transition between the cylinder and the foot plate has been damaged by this non-compliance.
Specifically chambers, having differing cross-sectional area's, where the smallest cross-sectional area may just be positioned there where the reaction force of the foot plate to said chamber is highest, may suffer damage. This problem occurs irrespective the chamber type, e.g. having different circumferential length of the cross sections of the chamber or not.
This invention deals additionally with solutions for the problem of optimizing ergonomical aspects, such as optimizing the size of the force during the stroke, and the force transfer by manual operation of a handle of a piston chamber combination, Current straight handles do not comply to the position of the hands of a user in rest, so that the hands need to turn a bit, grip the handle and transfer forces of a substantial magnitude through it, which may be unpleasant.